Field of Invention
The present invention relates to a vehicle speed selection method, and, particularly, to a vehicle speed selection method which may calculate a vehicle speed by receiving a vehicle speed signal of a vehicle speed sensor generation unit which satisfies a corresponding condition by checking a CAN communication state between an engine control unit and an ABS control unit, a communication state between the engine control unit and a wheel speed sensor, a confirmation on an exhaust gas emission regulation-applied target of the engine control unit and a confirmation on an automatic transmission-applied vehicle.
In addition, the present invention relates to a vehicle speed signal adjustment verification method, and particularly, to a vehicle speed signal adjustment verification method wherein whether or not the change in a vehicle speed calculated by the engine control unit is within a predetermined range, is determined as compared with the change of an accelerator pedal sensor, thus automatically changing the vehicle speed inputted into the engine control unit in a case where the change is not within the predetermined range.
Description of Related Art
Small- or middle-sized vehicles partially except for large-sized vehicles are using various vehicle speed detection sensors so as to calculate the speeds of the vehicles depending on a sale region or a displacement volume of the vehicle.
In the method for calculating the speed of a vehicle using a vehicle speed detection sensor, there may be a method of using a wheel speed sensor (WSS), a method of using a vehicle speed sensor (VSS), a method of using an ABS digital output, a method of using an ABS CAN message, and a method of using a transmission control unit output.
The method for calculating the speed of a vehicle using the wheel speed sensor (WSS) may be characterized in that the rotations of the wheels of a vehicle are measured using a hall sensor configured to count the rotations of the teeth (47 teeth/1 revolution) of a tone wheel secured to the wheels of the vehicle, and the engine control unit (ECU) receives the measured value, thus calculating the speed of the vehicle. Namely, the method for calculating the speed of a vehicle using the wheel speed sensor is directed to calculating the speed of a vehicle using the wheel speed sensor (WSS) which is configured to recognize 47 pulses per revolution of the wheel of the vehicle.
The method for calculating the speed of a vehicle using the vehicle speed sensor (VSS) is directed to measuring the revolution of the gear of a vehicle transmission using the vehicle speed sensor (VSS) configured to recognize 4 pulses per revolution of the vehicle transmission, so the engine control unit (ECU) may calculate the speed of the vehicle by receiving the measured value. Namely, the method for calculating the speed of a vehicle using the vehicle speed sensor is directed to calculating the speed of a vehicle using the vehicle speed sensor (VSS) which is able to recognize 4 pulses per revolution of the gear of the transmission. Here, the vehicle speed sensor may be a deceleration gear type sensor connected to the gear inside of the vehicle transmission.
The method for calculating the speed of a vehicle using the ABS digital output is characterized in that the anti-lock brake system (ABS) control unit transmits the signal of the wheel speed sensor (WSS) received from each wheel, to the engine control unit (ECU) so as to control the speed and posture of the vehicle, and the engine control unit (ECU) may calculate the speed of the vehicle using the received signal. Namely, the method for calculating the speed of a vehicle using the ABS digital output is directed to calculating the speed of a vehicle by receiving, from the ABS control unit, the value of the wheel speed sensor which is able to recognize 47 pulses per revolution of the vehicle wheel.
The method for calculating the speed of a vehicle using the ABS CAN message is characterized in that the signal of the wheel speed sensor (WSS) that the anti-lock brake system (ABS) control unit receives so as to control the speed of the vehicle and the posture of the vehicle is transmitted in the form of a CAN communication message to the engine control unit (ECU) based on a CAN communication, and the engine control unit (ECU) calculates the speed of the vehicle using the received signal. Namely, the method for calculating the speed of the vehicle using the ABS CAN message is directed to calculating the speed of the vehicle by receiving in the form of the CAN communication message the value of the wheel sensor which is able to recognize 47 pulses per revolution of the wheel of the vehicle, from the ABS control unit.
The method for calculating the speed of a vehicle using the TCU output (Transmission Control Unit Output) is characterized in that the transmission control unit (TCU) measures 4 pulses per revolution of the gear of the transmission using two pulse generator signals in the automatic transmission with respect to the revolutions of the gear inside of the automatic transmission, and the engine control unit (ECU) calculates the speed of the vehicle by receiving the measured value from the transmission control unit (TCU). Namely, the method for calculating the speed of the vehicle using the transmission control unit (TCU) output is directed to calculating the speed of the vehicle by receiving from the TCU a signal value 401 which is able to recognize 4 pulses per revolution of the gear of the transmission.
According to the conventional method for calculating the speed of the vehicle, the engine control unit (ECU) may calculate the speed of the vehicle based on any one of the above-described five methods depending on the vehicle option such as a sale region or the displacement volume. However, there is a problem in that the five methods may need different engine control units (ECU) and vehicle circuit wire connection depending on the options of the vehicle, so when assembling the vehicle or in a case of the after sale service based on the options of the vehicle, the speed of the vehicle may not be correctly measured because of possible errors in the circuit wiring of the vehicle or possible errors in application of the engine control unit.
For example, in a case where the engine control unit (ECU) using the method (method for calculating the speed of an automatic transmission vehicle) for calculating the speed of the vehicle using the transmission control unit output is installed at the automatic transmission vehicle, there may occur a problem in that the speed of the automatic transmission vehicle may not be properly measured. In addition, in a case where the engine control unit (ECU) using the method for calculating the speed of the vehicle using the wheel speed sensor (WSS) is used for a vehicle which has a vehicle circuit wire connection to which the vehicle speed sensor (VSS) is applied, there may occur a problem in that the speed of the vehicle to which the vehicle speed sensor (VSS) is applied, may not be correctly measured.
Therefore, it needs to develop a vehicle speed selection and vehicle speed signal adjustment verification method which makes it possible for the engine control unit (ECU) to accurately calculate the speed of the vehicle by any one of the above-mentioned five methods.
The information disclosed in this Background section is only for enhancement of understanding of the general background of the invention and should not be taken as an acknowledgement or any form of suggestion that this information forms the prior art already known to a person skilled in the art.